The disclosure relates to a chain link for a curved conveyor chain.
DE 100 27 229 A1 discloses a chain link for a curved conveyor chain. According to FIGS. 1 and 2, the chain link comprises a main body and a pin (not shown). The main body, which in this case is integral, comprises an articulation section 10 and a fork section 11. A driver means in the form of a flat supporting surface 3, by means of which material (not shown) to be conveyed can be taken along by friction, is provided on the upper side of the main body. Other driver means, e.g. catches, fins or brushes projecting vertically from the supporting surface, are also known as substitutes for the flat supporting surface. A multi-part main body is often provided in combination with the last-mentioned driver means.
The pin is of elongate design, being of circular cylindrical design over the entire length. In the articulation section a pin opening 9 is provided through which the pin passes in a manner which allows it to rotate relative to two axes. Here, the pin opening is configured similarly to FIG. 4 in EP 0 569 071 B2, i.e. the entire pin opening is provided fully in the main body, having a minimum cross-sectional area in the center, which widens toward the two orifices, ensuring that the pin has the desired ability for rotation. EP 1 311 446 B1 discloses an alternative articulation construction, in which the pin opening is intersected by a circular cylindrical aperture, in which a special articulation part is inserted. The articulation part in turn has an opening, which is matched to the pin. The last-mentioned design of articulation can transmit significantly higher tensile chain forces than that shown in DE 100 27 229 A1.
A fork recess 7 for accommodating the articulation section of an adjacent identical chain link is provided on the fork section in DE 100 27 229 A1. Two pin apertures in the form of circular cylindrical holes are furthermore provided in the fork section, serving to accommodate the pin of the adjacent chain link. A plurality of slide sections 4 made of fiber reinforced polytetrafluoroethylene (trade name “Teflon”) are furthermore provided on the main body, which is made of polyoxymethylene. The slide sections are intended to reduce the frictional forces imposed by the chain links on the chain guides.
The disadvantage of the chain link according to DE 100 27 229 A1 is that both the articulation section and the fork section are composed of the same material. During the operation of the conveyor chain, these materials rub directly against one another and produce squealing noises. This problem occurs especially with polyoxymethylene, the preferred material for the chain links of a conveyor chain. However, it can be observed in general that materials of the same kind, especially plastics, which rub against one another under load produce squealing noises owing to the stick-slip effect. One already known solution to this problem is to provide polyoxymethylene with various additives which improve its ability to slide. As a result, the tendency to generate noise is reduced. However, such materials are very expensive.
It is the object of the disclosure to reduce or completely avoid the above-described generation of noise in a low-cost manner.